Innovative packaging solutions for meat and meat products

In May, 949 exhibitors from all over the world presented their latest products, services and high-tech solutions for processing meats at the leading meat industry exhibition - IFFA 2010. At the exhibition, Prof Dr Horst-Christian Langowski* of the Fraunhofer Institute discussed the latest developments in packaging technology.

Prof Langowski, in your opinion, what trend has had the greatest influence on the globally important meat and meat products sector?

“The most important trend for meat and meat products has to be the growth of the convenience product sector. Butcher shops and classic supermarket meat counters are being steadily replaced by the refrigerated sections of discounters. Here, consumers are able not only to purchase processed meat products such as cooked and boiled sausages, but also pre-packaged fresh meats. Freshly cut meat, including spiced meats, sold in the refrigerated section make up a growing part of the convenience sector.”

What role does packaging play in the convenience sector?

“Without a suitable packaging concept, this sector could not even exist. The desire for greater convenience is satisfied solely by the packaging. The use of modified atmosphere packaging makes it possible to markedly increase the shelf life of meat products. Within the self-service market sector, fresh meats and sausages in plastic modified atmosphere packaging represent one of the fastest growing areas.”

What technical aspects must be watched particularly closely with modified atmosphere packaging?

“In each case it is essential that the packaging materials used are able to provide a functional barrier against gases. Otherwise, the composition of the gases in the package headspace would be changed too much by the entry of other gases. Even though we have been grouping fresh meats, meat and sausage products together in this discussion, there are actually very different requirements for each when it comes to the packaging and the protective gas to be used. As a result, the packaging concepts for sausages and fresh meats need to be dealt with separately. With closed packages, the colour and appearance of the meat products are a consumer’s primary way of determining quality. Products which have been processed differently place different demands on the packaging to be used.”

What requirements must each packaging solution satisfy?

“Modern packaging for meat products that are sensitive to the visible spectrum of light should contain a number of elements: a protective gas atmosphere that contains the technically feasible minimum of oxygen, high-barrier films that prevent the entry of oxygen and, in future, oxygen-absorbers that are able to absorb any residual oxygen remaining in the protective gas atmosphere or dissolved within the product itself as quickly as possible. In this concept, the utilisation of oxygen scavengers is an effective support for the protective gas technology, making it possible to produce an atmosphere within the packaging that is nearly free of oxygen - a prerequisite for extending the shelf life of foods which are susceptible to oxygen.”

According to what you are saying, light and oxygen have a particularly marked effect on meat products. What is the best way to protect them?

“Even with the use of a protective gas atmosphere, the residual oxygen in the headspace, dissolved within the product itself or in the pores amounts to one or two per cent. This is enough, particularly with exposure to light, to result in a rapid decrease in quality. The objective is to use oxygen scavengers to remove this residual oxygen, so that it will be possible to sell consumers these products in the transparent packaging they desire, using the illumination that is standard in stores, all while maintaining an almost unchanging level of quality. These oxygen scavengers are currently being developed and tested. They are considered to be an example of active packaging. These are packaging materials made from conventional polymeric materials into which additional characteristics have been integrated.”

What is such active packaging capable of?

“Standard packaging protects against oxygen in the air, moisture, light and infection by harmful organisms - active materials are able to perform even more functions. In addition to consuming oxygen, examples include filtering out light and radiation from the near UV spectrum. Antimicrobial packaging can provide additional protection against microorganisms on the surface. Raw meat products are generally packaged with an oxygen content of as much as 80% in order to maintain the appealing red colour of the meat. In this regard, a UV filter in the packaging material can offer the product additional protection against high-energy radiation, for UV radiation increases meat’s vulnerability to colour loss. The situation is different for all cured meat products. These products are sensitive to the visible light spectrum, with the red colouring, nitrosomyoglobin, acting as a sensitising agent. Such cured meat products quickly turn grey when exposed to light and oxygen. There are only two possibilities for providing these products with optimum protection: the exclusion of light or the exclusion of oxygen. Due to the fact that the trend is towards transparent packaging, practical packaging concepts have to focus on minimising the oxygen content.”

How does such antimicrobial packaging work?

“A key factor in the spoilage of meat and meat products is the uncontrolled growth of microorganisms which cause unpleasant sensory perceptions or even, in extreme cases, illness. Packaging materials that help to suppress the growth of unwanted bacteria on the surface are currently being developed. Conventional packaging films are coated with a layer from which minuscule quantities of active antimicrobial substances (eg, sorbic acid) diffuse to the surface of the food product and exert their antimicrobial properties. An important prerequisite for the practical utilisation of such films is that the entire surface of the meat must be in direct contact with this packaging material. Even extremely small quantities of active antimicrobial substances can suppress the microflora on food surfaces, making them an effective component of the hygiene chain.”

*Prof Dr Horst-Christian Langowski is the Director of the Fraunhofer Institute for Process Engineering and Packaging (IVV) in Freising and holder of the Chair for Food Packaging Technology at the Technical University of Munich-Weihenstephan.